The explosion in Internet usage and huge government funding initiatives in digital libraries have drawn attention to research on digital libraries. Whereas the traditional focus of digital library research has been on the technological development, there is now a call for user-focused research. Although millions of dollars have been spent on building "usable" systems, research on digital libraries has shown that potential users may not use the systems in spite of their availability. There is a need for research to identify the factors that determine users' adoption of digital libraries. Using the technology acceptance model (TAM) as a theoretical framework, this study investigates the effect of a set of individual differences (computer self-efficacy and knowledge of search domain) and system characteristics (relevance, terminology, and screen design) on intention to use digital libraries. Based on a sample of 585 users of a university's award-winning digital library, the results strongly support the utilization of TAM in predicting users' intention to adopt digital libraries, and demonstrate the effects of critical external variables on behavior intention through perceived ease of use and perceived usefulness. All of the individual differences and system characteristics have significant effects on perceived ease of use of digital libraries. In addition, relevance has the strongest effect on perceived usefulness of digital libraries.